{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-115889", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-23T19:37:27.176Z", "datePublished": "2026-10-23T21:23:27.669Z", "dateUpdated": "2026-10-23T21:23:27.669Z"}, "containers": {"cna": {"title": "Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation", "problemTypes": [{"descriptions": [{"cweId": "CWE-197", "lang": "en", "description": "CWE-197: Numeric Truncation Error", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-843", "lang": "en", "description": "CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.9, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm"}, {"name": "https://github.com/bytecodealliance/wasmtime/pull/12613", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/pull/12613"}, {"name": "https://github.com/bytecodealliance/wasmtime/pull/14818", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/pull/14818"}, {"name": "https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0"}, {"name": "https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa"}, {"name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19"}, {"name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0"}], "affected": [{"vendor": "bytecodealliance", "product": "wasmtime", "versions": [{"version": "< 36.0.19", "status": "affected"}, {"version": ">= 37.0.0, < 43.0.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-23T21:23:27.669Z"}, "descriptions": [{"lang": "en", "value": "Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0."}], "source": {"advisory": "GHSA-897f-g5gm-fmxm", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "wasmtime", "vendor": "bytecodealliance", "versions": [{"status": "affected", "version": "< 36.0.19"}, {"status": "affected", "version": ">= 37.0.0, < 43.0.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0."}], "id": "CVE-2026-115889", "lastModified": "2026-10-23T22:16:58.550", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.9, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.1, "impactScore": 6.0, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-23T22:16:58.400", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/pull/12613"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/pull/14818"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-197"}, {"lang": "en", "value": "CWE-843"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}